Logik LOG32lw782

**selldoor** · 01-12-2014, 12:33 PM

Re: Logik LOG32lw782

I would concentrate on getting a decent picture of your power supply and posting it using manage attachments so it can be expanded. Around 2mb and you need to get the lighting right.

What I find odd is that I cant see any normal testing being done- perhaps you have done it and just not reported it. Usual thing is to check the secondary
voltages at the connector to the main board. If there are none or they test shakey then go back to testing the primary voltage.

**joehezzer** · 01-12-2014, 12:44 PM

Re: Logik LOG32lw782

just found this

https://www.badcaps.net/forum/showthread.php?t=15313
according to this i have voltage at pin 1 on pl803

**joehezzer** · 01-12-2014, 12:47 PM

Re: Logik LOG32lw782

tom66 posted this

Okay, I got it to power on after a lot of coercing.

I found a service manual for a similar TV. The power supply is different (I believe it adds support for plasma panels too), but a lot of the component designators are the same and the layout is similar, so it might be helpful. I've attached the manual.

Anyway, there's a pin called STBY on PL803. When it is not working, it is at 0.09V. When it is working, it is at 2.5V. Could the control board be telling the PSU to turn on using this? Why isn't it going high normally?

PL803 when ON:
#1: 3.204V
#2: 0.512V
#3: 0.050V - 0.150V (climbs slowly)
#4: 3.364V
#5: 2.578V
#6: 0.050V
#7: 34.03V (for tuner?)
#8: 11.08V
#9: 0.009V
#10: 0.009V

PL803 when set is in standby:
#1: 0.001V
#2: 0.000V
#3: 0.001V
#4: -0.003V
#5: 0.060V
#6: 1.754V
#7: 33.02V (decays slowly)
#8: 0.030V
#9: 0.009V
#10: 0.009V

PL803 when trying to start:
#1: 0.010V
#2: 0.000V
#3: 0.150V - 0.180V
#4: 0.323V
#5: 0.059V
#6: 0.055V
#7: 32.40V (decaying slowly)
#8: 0.128V
#9: 0.009V
#10: 0.009V

This is odd, because I would expect pin #5 to be the signal from the mainboard to turn on the TV, but there is no significant signal on it.

But, when scoping it... I think it has a clue. While it is trying to turn on it goes crazy! It changes between several waveforms - at one point 2.5Vp-p - but eventually goes almost completely dead. Sometimes these waveforms show up when the set is switching on and sometimes not. And sometimes pressing the power button on the remote makes this pin go high for maybe half a second, then go low. Something is stopping it fully starting.

I've ordered some caps, but it seems less and less likely to be a cap issue now.

Maybe I should try jumpering this to 2.5V to get the set to switch on?

**joehezzer** · 01-12-2014, 12:49 PM

Re: Logik LOG32lw782

Originally posted by selldoor

I would concentrate on getting a decent picture of your power supply and posting it using manage attachments so it can be expanded. Around 2mb and you need to get the lighting right.

What I find odd is that I cant see any normal testing being done- perhaps you have done it and just not reported it. Usual thing is to check the secondary
voltages at the connector to the main board. If there are none or they test shakey then go back to testing the primary voltage.

i was unsure of pin layout as none had voltage readings on.

**joehezzer** · 01-12-2014, 12:56 PM

Re: Logik LOG32lw782

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**joehezzer** · 01-12-2014, 01:21 PM

Re: Logik LOG32lw782

PL803 when ON:
#1: 3.46V
#2: 0.003V
#3: rises then drops a bit all over the place V - 0.150V (climbs slowly)
#4: 0.00V
#5: 0.010V
#6: 3.010V
#7: 00.03V (for tuner?)
#8: 00.00V
#9: -0.000V
#10: -0.000V

could this be duff psu then

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**joehezzer** · 01-12-2014, 01:46 PM

Re: Logik LOG32lw782

just found a pdf file with all the right values. will have a mess in the week. i have also found one of these in the pic with a bulge in it not sure if i am right but is it a capacitor!! it reads 15n j 600v 373 mkp/mkp

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**joehezzer** · 01-12-2014, 03:24 PM

Re: Logik LOG32lw782

Originally posted by joehezzer

just found a pdf file with all the right values. will have a mess in the week. i have also found one of these in the pic with a bulge in it not sure if i am right but is it a capacitor!! it reads 15n j 600v 373 mkp/mkp

15nf 600v plastic film cap is that right

**multimeter** · 01-12-2014, 03:28 PM

Re: Logik LOG32lw782

Originally posted by joehezzer

15nf 600v plastic film cap is that right

yes,these are a common failiure in samsung bn*** power supplys also.

**joehezzer** · 01-12-2014, 03:34 PM

Re: Logik LOG32lw782

just looking on maplins cannot seem to find the right one

**multimeter** · 01-12-2014, 03:44 PM

Re: Logik LOG32lw782

try cpc,rs components,or farnell....

**joehezzer** · 01-12-2014, 03:47 PM

Re: Logik LOG32lw782

Originally posted by multimeter

try cpc,rs components,or farnell....

cheers

**joehezzer** · 01-15-2014, 02:21 PM

Re: Logik LOG32lw782

ok so i have changed the plastic film caps, now testing the voltage

PL803 when ON:
#1: 3.38V
#2: 0.003V
#3:0.76v
#4: 1.60V
#5: 0.010V
#6: 3.00V
#7: 00.06V (for tuner?)
#8: 00.00V
#9: -0.000V
#10: -0.000V

some of the readingings are slightly different

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**joehezzer** · 01-16-2014, 04:57 AM

Re: Logik LOG32lw782

.

**selldoor** · 01-16-2014, 05:41 AM

Re: Logik LOG32lw782

It is a nice bright day up here - if its same in Devon take the boards outside
and try for some better pictures. They are just not big enough or bright enough for troubleshooting. You have got the connector to the main board connected whilst testing?

**selldoor** · 01-16-2014, 05:53 AM

Re: Logik LOG32lw782

Dont know if its the same but did you see this part that tom posted

"I haven't been turning it on properly, that's why! You need to turn on the switch AND press the power button to turn it on."

**joehezzer** · 01-16-2014, 06:06 AM

Re: Logik LOG32lw782

will get some pics now

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**joehezzer** · 01-16-2014, 06:09 AM

Re: Logik LOG32lw782

Originally posted by selldoor

Dont know if its the same but did you see this part that tom posted

"I haven't been turning it on properly, that's why! You need to turn on the switch AND press the power button to turn it on."

no, i cannot see any separate rocker switch anywhere

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